The invention is based on an apparatus for disconnecting individual cylinders of an internal combustion engine as defined hereinafter.
Such an apparatus is known from German Offenlegungsschrift 37 18 714. This apparatus has a fuel injection pump, with at least two partial suction chambers, separate from one another and assigned to different cylinders of the engine. The partial suction chambers communicate with a common feed pump via separate lines. One valve is disposed in each of the lines from the feed pump to the partial suction chambers. When the valves are open, fuel is pumped into the applicable partial suction chamber by the feed pump and to the associated engine cylinders at high pressure by the fuel injection pump. By the closure of one of the valves, the applicable partial suction chamber can be inactivated from supplying fuel from the feed pump, so that no further fuel is supplied to the associated cylinders, and they merely trail along.
Although the closure of the valve does inactivate the partial suction chamber from the feed pump quickly, nevertheless the idle volume of the fuel injection pump, which under some circumstances may be considerable, means that more fuel continues to be pumped to the cylinders that are to be inactivated, so that there is a considerable delay before they are inactivated. If the cylinders are intended to be inactivated only briefly, complete inactivation cannot be achieved with the known apparatus.